1. Department of Anesthesiology and Critical Care Clinica Universidad de Navarra Pamplona Spain
2. Instituto de Investigación Sanitaria de Navarra Pamplona Spain
3. Research Support Service, Central Clinical Trials Unit Clinica Universidad de Navarra Pamplona Spain
4. Department of Radiology Clinica Universidad de Navarra Pamplona Spain
5. Department of Neurosurgery Clinica Universidad de Navarra Pamplona Spain
6. Department of Neurology Clinica Universidad de Navarra Pamplona Spain